Mayor de Blasio kept the little people waiting for an hour yesterday before presenting his inaugural $75.5 billion budget — but it wasn’t better late than never. The mayor didn’t present a balanced budget as state law requires. He didn’t really even present a budget — not one from a mayor.

The mayor acted yesterday as if he were still a city councilman or the public advocate — or a long-shot mayoral candidate. He obsessed over little things guaranteed to get applause from important constituencies — but missed the big picture.

Budget day is one of any mayor’s few chances during the year to remind the public that the city faces big financial challenges, such as the fact that for the fiscal year that starts in July, it will spend 31 percent of its tax dollars on pensions and health benefits for city workers.

But de Blasio passed on the opportunity. He spent his remarks reminding us that he is “progressive, responsible and honest.” Apparently, that means not worrying much about budgets.

The mayor highlighted all sorts of things that may be interesting — “income inequality in America is at levels not seen since the roaring ’20s”; only one in four public-school graduates is “college ready”; the rent is still too damned high. But none of that has anything to do with the fact that New York must come up with $57.2 billion from its taxpayers for next year. (The rest of our cash comes from Albany and the feds.)

And where the new mayor was most interested in his budget is where it doesn’t matter much, anyway. He said he’ll hike this year’s budget line for snow removal from $57 million to $92 million. Yep, it is snowing. But that extra $35 million in spending isn’t even a tenth of 1 percent of the budget document de Blasio’s supposed to be building.

Same thing with other things that, good or bad, are in this context irrelevant. There’s $3 million for an inspector-general for the NYPD — something that pleases the anti-stop-and-frisk crowd, but matters little to overall spending. Same for the $1.8 million for city inspectors to enforce the new law that forces businesses to provide paid sick leave.

De Blasio also wants to “begin to end” the “budget dance” — former mayors’ habit of slashing politically important items so that the City Council pose heroically as it adds them back. So he restored $59 million in pretend fire cuts that Mayor Michael Bloomberg always made, only to see the council restore them.

Sorry: The council’s not going to spend its freed-up time figuring out, say, how to cut public-worker health-care costs.

Plus, de Blasio is showing a bad habit: He doesn’t mind throwing more money at a problem without demanding reform. For example, he wants to spend $52.5 million more to subsidize public housing — even though he’s already shot down a Bloomberg-era plan to let the public-housing authority sell some its vacant land to developers to help it out financially.

What about the big stuff?

Sure, de Blasio said the city faces “unprecedented fiscal challenges” because of “more than 150 labor contracts left unresolved” by Bloomberg.

But after a year of slamming Bloomberg for not setting aside money in the budget for retroactive raises for city workers, de Blasio started off his budgeting career . . . not setting aside money in the budget for retroactive raises for city workers.

The mayor’s projected wage and salary costs for next year are $22.5 billion — only $200 million higher than Bloomberg’s $22.3 billion projection, not the billions the eunions want.

Sure, de Blasio can say he doesn’t want to tip his hand as he negotiates with unions. But the real reason he didn’t budget for retroactive raises is that there’s no money long-term — the same problem that faced Bloomberg. Even without the raises, de Blasio faces a $1.1 billion deficit his second year in office.

And this year’s budget is out of whack, too — despite de Blasio’s claim of a “zero” deficit.

Consider: The mayor relies on $530 million from a new tax on the wealthy — even though Gov. Cuomo and state Senate leader Dean Skelos have already said they won’t impose such a tax.

Yes, Bloomberg also relied on new tax money from the state for his first budget — but the governor hadn’t already flatly nixed the idea.

This use of phantom funds makes de Blasio look less heroic when he pledges to keep $1.3 billion aside for future retiree health-care costs and other rainy-day needs: When that state money doesn’t appear —and if de Blasio will never tell the truth to the unions — guess where this health-care “trust fund” cash will go?

The mayor noted in passing that “the previous administration was given an artificially high level of credit” for budget management.

Yep. And de Blasio’s in no danger of that.

Nicole Gelinas is a contributing editor to the Manhattan Institute’s City Journal.